In the relevant industries, it is often required that fastening screws be tightened by a limited, controlled force, in order to avoid damage to the equipment or to fulfill other conditions, e.g. in case of a cover with a rubber seal which must not become over-squeezed.
Other, related examples, are cases where it is requested that once tightened, the screw cannot be slackened by ordinary tools such as a screwdriver, or at all.
Alternatively, a demand may be posed that it would be possible to unscrew the screw, but there will be clear and unmistakable indication that the screw has been tampered with by an unauthorized person.
The invention aims at proposing a solution satisfying any and all of these requisites.
It is a further object of the invention that the screw heads be produced by forging.